Fire sprinkler systems have been used in the United States to protect warehouses and factories for over one hundred years. In a fire sprinkler system, a fire sprinkler is positioned near the ceiling of a room where hot “ceiling jets” spread radially outward from a fire plume. When the temperature at an individual sprinkler reaches a pre-determined value, a thermally responsive element in the sprinkler activates and permits the flow of water as a water jet through a duct toward a deflector. The deflector redirects the water jet into thin streams or “ligaments” that break up into droplets due to surface tension. The water droplets serve three purposes: (1) delivering water to the burning material and reducing the combustion rate, (2) wetting the surrounding material and reducing the flame spread rate, and (3) cooling the surrounding air through evaporation and displacing air with inert water vapor.
When fire sprinklers are located close to each other, as shown in FIGS. 3 and 4, the risk of “cold soldering” becomes a concern. Cold soldering occurs when a first fire sprinkler disperses a fire suppressing or extinguishing substance that directly cools a second fire sprinkler and prevents the second fire sprinkler from properly responding and activating. Thus, there is a need in the fire suppression and extinguishment field to create an improved fire sprinkler that reduces or eliminates the risk of cold soldering. This invention provides such improved fire sprinkler.